En Tue, 03 Nov 2009 17:36:08 -0300, iu2 <isra...@elbit.co.il> escribió:
On Nov 3, 7:49 pm, Matt McCredie <mccre...@gmail.com> wrote:
iu2 <israelu <at> elbit.co.il> writes:
> Having a file called funcs.py, I would like to read it into a string,
> and then import from that string.
> That is instead of importing from the fie system, I wonder if it's
> possible to eval the text in the string and treat it as a module.
mymodule = types.ModuleType("mymodule", "Optional Doc-String")
with file('funcs.py') as f:
txt = f.read()
exec txt in globals(), mymodule.__dict__
sys.modules['mymodule'] = mymodule
Thanks, it seems simpler than I thought.
I don't fully understand , though, the exec statement, how it causes
the string execute in the context of mymodule.
Sometimes you don't even require a module, and this is simpler to
understand. Suppose you have a string like this:
txt = """
def foo(x):
print 'x=', x
def bar(x):
return x + x
"""
you may execute it:
py> namespace = {}
py> exec txt in namespace
The resulting namespace contains the foo and bar functions, and you may
call them:
py> namespace.keys()
['__builtins__', 'foo', 'bar']
py> namespace['foo']('hello')
x= hello
exec just executes the string using the given globals dictionary as its
global namespace. Whatever is present in the dictionary is visible in the
executed code as global variables (none in this example). The global names
that the code creates become entries in the dictionary. (foo and bar;
__builtins__ is an implementation detail of CPython). You may supply
separate globals and locals dictionaries.
--
Gabriel Genellina
--
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